Hacking a pressure sensor to track gradual motion along marine faults

MBARI/University of Washington

The modified pressure sensor is now being tested at the bottom of Monterey Bay.

Deep below the ocean’s surface, shielded from satellite signals, the gradual movement of the seafloor — including along faults that can unleash deadly earthquakes and tsunamis — goes largely undetected. As a result, we know distressingly little about motion along the fault that lies just off the Pacific Northwest coast.

University of Washington oceanographers are working with a local company to develop a simple new technique that could track seafloor movement in earthquake-prone coastal areas. Researchers began testing the approach this summer in central California, and they plan to present initial results in December at the American Geophysical Union’s annual meeting in New Orleans.

Their approach uses existing water-pressure sensors to cheaply measure gradual swelling of the seafloor over months to years. If successful, the innovative hack could provide new insight into motion along the Cascadia Subduction Zone and similar faults off Mexico, Chile and Japan. The data could provide clues about what types of earthquakes and tsunamis each fault can generate, where and how often.